Solid‐State Ionics: Studies on the Solid Electrolytes in the System Ag2 X ‐ AgI ‐ HgI2

Abstract

Compositions exhibiting high ionic conductivity in the solid state at ambient temperature were determined in the system to be , , , or . The electrical conductivities of these compounds were measured by means of the 1000 Hz a‐c bridge and the values obtained at 25°C were , , , and , respectively. The activation energies for conduction were calculated from the conductivity curves to be 2.95, 3.24, 3.34, and 3.58 kcal/mole for the above four compounds. In order to interpret the high ionic conductivities and the low activation energies for conduction of these compounds, the crystal structure was analyzed in detail by means of powder x‐ray diffraction, and it was found that N‐l had the same structure as that of . The cations in N‐l were statistically distributed over forty‐two sites of 6(b), 12(d), and 24(h) of the space group Im3m and the anions were randomly distributed at the corner and the center of the cell. N‐2, N‐3, and N‐4 had somewhat different structures from that of N‐l. The cations in N‐2, N‐3, and N‐4 were statistically distributed over thirty sites of 6(b) and 24(h), and the anions were distributed in the same manner as N‐l. The proposed crystal structures of the four solids were verified by comparing the calculated values of the relative intensities of the x‐ray diffraction lines with the experimental values. The distribution factors were defined and were discussed together with the activation energies for conduction.